Fuel-injection system



April 3, 1928. 1,664,611

L. O. FRENCH FUEL INJECTION SYSTEM Filed April 29 1925 (I liressure Vf/rg I Patented Apr.-3,.1928.

PATENT OFFICE.

ouis 0. 33311011, or MILWAUKEE, wrsconsm.

FUEL-INJECTION SYSTEM.

Application filed April 29, 1925. serial No. 28,676.

The invention relates to fuel injection systems, and more particularly to those systems wherein an electro-magnetically-operated fuel-metering device, is used to control the amount of fuel delivered to the engine and directly or indirectly control the time at which such fuel is delivered.

In injection systems of the type referred to, switch mechanism is provided for controlling the supply of current to the electromagnet of the metering device, and it is one of the objects of this-invention to provide controlling mechanism which is automatically actuated through a speed responsive device so as to provide for furnishing varying amounts of fuel at varying periods and through means under manual control to vary the action of the speed responsive device to provide for operating the engine through difi'erent speed ranges.

In injection type engines the manner of introducing the fuel, such as'directly into the maincombustion chamber or indirectly through a small chamber associated with the main combustion .chamber, the shape of these chambers, the form of thefuel spray, the amount of compression used, and the type of ignition employed, are factors to be considered in regulating the time of injection of the fuel into the engine so as to obtain the best power characteristics for the articular design, It is another object of t is invention to'elfect thevariation in the cyclic timing of the fuel-injection through the advancing or r'etardingof the closing of the control 'clrcuit for the electro-magnetically-operated fuel metering device in accordance with the speed and best power characteristics or power curve of the engine.

A further object of the invention is to provide control switch mechanism for the electromagnetically-operated fuel-metering .device of a fuel injection system wherein the movable switch contact is operated by an engine-driven cam associated with mechanism for adjusting it lengthwise and angularly whereby the duration and timing of the operation of the said device may be varied to vary the amount of fuel injected into the en- .gine and the timing of the fuel injections.

The invention further consists in the several features hereinaftenset forth and more manually controlled collar 22 particularly defined by claims at the conclusion hereof.

In the drawings: Fig. 1 is a vertic'al'sectlonal view through a control device embodymg the invention, taken on the line 1-1 of Fig. 3;

Fig. 2 is a sectional view on the line 2-2 of Fig. 1;

Fig. 3 is a sectional view taken on the line 33 of Fig. 1;

Fig. 4 is a semi-diagrammatic view of a fuel injection system including the control device embodying the invention.

In the drawings the numeral 5 designates a two-part casing, 6 a switch casing mounted on the casing 5 for angular adjustment relative thereto, as by means of screws 5 in casfitted to the casing 5 whereby the shaft is journalled inthe casing and prevented from moving upwardly.

'An engine-driven shaft 11 has a spider 12 secured to rotate therewith by screws 13. This spider has abore 14 and a sleeve 15 has a portion slidably mounted in the bore 14 and on the shaft 8 to move lengthwise thereof. This sleeve movement is effected by any suitable governor associated with the spider 12. As shown, the oppositely disposed arms of the spider have levers lfipivotally mount-- ed thereon, their'forked ends 17 being provlded with pins 18 mounted in an annular groove 19 formed in the upper part of the sleeve 15, their outer ends carrying the weights 20. Aspring 21,- acting opposition to the governor weights, is interposed between the upper end of the sleeve 15 and a mounted on the shaft 8.- The collar 22 is moved manually by a' lever 23 pivotally mounted on the casing and-having forked ends 23", provided with pin projections engaglngh n the groove of said collar, and an exteriorly disposed operating arm 24.

The sleeve 15 is secured. to a key 25 slidably mounted in a keyway 25 in shaft 8 and has diametrically disposed slots 26, preferably of varying angularity, and pins 26 mounted in the hub of the spider 12 work in these slots and form driving connections between said spider and the sleeve 15 and the shaft 8 keyed thereto. I

A thrust bearing 27 is disposed between the lower end of the shaft 8 and the upper end of the shaft 11, and a ball bearing 28 is located between the hub of the spider l2 and the casing 5. f

A cam 29, slidably mounted on the shaft 8, is secured to the key 25 which extends upwardly from the sleeve 15 through a slot in the bearing 9. Thus, these parts 29, 25 and 15 may move together lengthwise of the shaft 8.

A movable switch contact 30 is suitably pivotally mounted at 31 in the casing 6 and carries a ball 32 urged against the cam 29 by a spring 33 and engages a fixed contact 34 on a bracket 35 secured to the casing 6, above a plate 36 of insulation, by suitably insulated screws 37. A conductor 38 has its terminal member 39 passed through an insulating bushing 40 and secured to the bracket by a current flow in the control circuit or circuits may be varied.

\Vith this construction, as the shaft 8 is rotated through spider 12, pins 26, sleeve 15 and key 25 by the engine-driven shaft 11, the governor levers 16 cause an up and down movement of the sleeve 15, and hence the cam 29, to vary the duration of the circuitclosed period and at the same time the slots 26 permit a relative angular movement betweenthe shaft 11 and the shaft 8 with the result that, in the present instance, as the cam moves upwardly it is also rotated backwardly through certain predetermined angleswith respect to the shaft 11 so that injection for shorter circuit-closing periods produced by the cam occur later than the longer circuit-closing periods.

The shape of the slot is preferably so related to the charge period and speed that the injection of fuel and the amount furnished will occur at such times as will produce the greatest "power for any given speed. The power curve of the engine is obtained by trial runs with different settings of the switch relative to the cam to give best power characteristics at different speeds, as by the fuel injection may be had for different positions ofthe cam 27 relative to the switch,

and that those positions are determined by the governor whose speed range is varied by the operators adjustment of the tension of the spring 21 through the movement of the collar 22. As an initial aid to starting, the

switch casing 6 is shown as provided with a handle 43 for rotating it to secure an early injection of an overload charge of fuel, since the circuit-closing period is then at a maximum, and thereafter the handle 43 is returned to a running position and. the governor then functions as above described. The downward movement of the collar 22 also acts to accelerate the speed of the engine and to provide increased amounts of fuel, when desired, over that which the governor action is furnishing the engine. The slots 26 with the pin 26 limit the travel of the cam 29 lengthwise of the shaft 8.

A current distributor, either directly or indirectly associated with the circuit-closing switch, is provided by making the cover 7 of insulating material and associating fixed contacts 44 therewith to form a commutator track over which a conductor brush 45 moves. This brush is slidably guided in a metal carrier 46 and urged against the track by a spring 47. A support 48 is mounted on the upper threaded end of the shaft 8 and insulated from said carrier by an insulating plate 49. Screws 50, insulated from said carrier by insulating washers 51 and plate 49, pass through arcuate slots 52 in the carrier and plate and into the support- 48 to secure the carrier thereto and permit of an angular llltl adjustment of the brush relative to the commutator. A spring-pressed brush or contact 53 mounted in the cover engages the carrier in axial alinement with the shaft 8. The contacts 44 and the brush 53 are provided with suitable terminal connections, such as the studs 54 and binding nuts 55 and the threaded socket 56. Thus, as the shaft8 is revolved the current passing through brush 53 is conductedto the carrier 46 and brush 45 and successively distributed to the contacts 44 which are electrically connected with the control electrom'agnets ofthe metering devices. p

In Fig. 4 Ihave shown one type of fuel injection system, more particularly shown and described in my copending application so magnetlc material ust prevents the arma- Serial No. 728,805, filed July 28, 1924, in which the control mechanism above described may be used. This system includes a fuel supply tank 57 connected by piping to a pump 58 of any suitable construction and actuated by the engine or other suitable means and delivering fuel to a pressure pipe or line 59 in which the fuel is retained at a substantially predetermined constant pressure in any suitable manner, as by a pressurc valve 60 of any suitable construction, loaded to the desired amount to maintain a pressure head of fuel in the line 59 of the desired value. From the valve 60 fuel may bereturned to the supply tanks through a pipe 57'. Branch pipes 61 connect pipe 59 with electro-magnetically-controlled valves 62 from which the fuel passes through pipes 63' to fuel injectors 64 of the automatic or fuel-pressure-opened spring-closed type, mounted in the heads 64' or cylinders of the engine;

Each of the valves 62- here shown includes amulti-part casing 65 of non-magnetic material, the upper end of which is closed off by the 'electro-magnet 66', comprising a core 66, a shell 67 of magnetic material, an energizing coil 68 within the annular space between the core and the sides of the shell, and an annular plate 69 of non-magnetic .material having its edges mounted in recesses in .the core 66 and the lower flanged end'of the shell and secured thereto in a fluid-tight manner. The lower flanged end of the shell seatson an annular shoulder 70 formed in the upper end of casing 65 and is secured thereto in a fluid-tight manner by a gland nut 71. The valve 72, of the needle type, is guided in the casing 65 and normally held against its seat on-inlet member 73 by a spring 74, said member 73 being secured to the casing 65 by an inwardly flanged nut 7 5. The upper end of the stem of the valve 72 is threaded and adjustably mounted and secured in a threaded boss 76 of the armature 77 of the magnet. Fuel from the pipe 61 passes through the passage in the member 73, when the valve is open, around the stem and through passages 7 8 and chamber 79 to the pipe 63. A non-freeze pin 80- of nonture from contacting with the attractive face of the magnet. When the coil is energized the magnetic flux set up passes through the 0011 and shell across therelatively short gaps .between the shell and armature and the armature and core and exerts a lift on the valve equal to the small difference between fuel pressure in pipe 60, acting to open the valve, and the greater spring pressure tending to close the valve, and thus opens the valve.

- The time and duration of opening the valves are determined by the time and duration of energization of the electromagnet 66 by the switch mechanism previously deof the electro-magnets 66, whose other terminals are grounded. The other side of the battery is connected by the conductor 38 to the insulated bracket 35 and contact 34. Thecontac-t30 is groundedpand a condenser is connected across the switch contacts to reduce arcing; For a quick response of the elctro-magnet, the time constant may be made small by connecting a resistor 86 in v series with each energizing coil. With this construction the' shaft 8 is rotated at cyclic speed and opens and closes the circuit through contacts 30 and 34 at the desired time in the manner previously described, the closing of the circuit being made during the time the brush 45 is in contact with one ofthe contacts 44 and thus energizing the coil connected with this respective contact, the circuit being battery 81, conductor 82,

brush 45, conductor 83 including resistance 86, coil 68, through ground to contact 30, contact 34, conductor 38 back to thebattery, thus causing the valve 72 to open to allow fuel to flow from pipe 59 to pipe 63 under pressure, thereby unseating the valve of the injector 64 and delivering the fuel to the particular enginecylinder'then ready to re ceive its charge at the desired time and in the desired amount.

In a similar manner the control switch mechanism may be used in those systems where the electro magnetically operated valve is the fuel injector valve. It may also be used in those systems Where the electromagnetically-operated valve is the suction or by-pass valve of the fuel pump, as shown and described in my copending applications: Serial No. 666,840, filed Oct. 5, 1923; Serial No. 712,830, filed May 12, 1924; and Serial No. 1,328, filed Jan. 8, 1925, renewed July 18, 1927, but in the case of the suction valve as shown in said applications Serial Nos. 660,840 and 1,328, the automatic advancing or retarding feature would be used to determine the ending of the energization period and the relief 42 would be inverted so that the circuit-closing period would be varied to hold the suction valve open for varying periods of time, from a time just before the end of the suction stroke of the pump to a time during the delivery stroke of the pump. Furthermore. when the switch'mechanism above described is used with that system shown in my application Serial No. 1,328, and the shaft 8 is driven at cyclic speed, the distributor is associated with the fluid-pressure-operated switch of that application.

Furthermore, the circuit control mechanism herein described may be used in connection with the metering control electromagnet of other forms of fuel-metering devices.

I desire it to be understood that this invention is not to be limited to any particular arrangement or construction of parts except in so far as such limitations are included in the claims. i

hat I claim-as my'invention is:

1. In a circuit controller for fuel injection systems, the combination with a switch in eluding a movable contact, of an engine-driven timing shaft, a cam on said shaft for controlling said movable contact, said cam being slidably mounted on said shaft and having a variable profile shiftable relative to said movable Contact to vary the duration of the circuit closing periods of said switch to vary the duration of the injection period, and means for angularly shifting said cam and shaft simultaneously with the shifting of said cam on said shaft to vary the time of injection as the injection period is varied.

2. In a circuit controller for fuel injection systems, the combination with a switch including a movable contact, of an engine-driven timing shaft, a cam on said shaft for controlling said movable contact, said cam being slidably mounted on said shaft and having a variable profile shiftable relative to said movable contact to vary the duration of the circuit closing period of said switch to vary the duration of the injection period, a governor, and means controlled by the governor for angularly shifting said cam and shaft simultaneously with the shifting of said Cam on said shaft to vary the time of injection as the injection period is varied.

In a circuit controller for fuel injection systems, the combination with a switch including a movable contact, of an engine-driven timing shaft, a cam on said shaft for controlling said movable contact, said cam being slidably mounted on said shaft and having a variable profile shiftable relative to said movable contact to vary the duration of the circuit closing period of said switch to vary the duration of the injection period, a governor, means controlled by the governor for angularly shifting said cam and shaft simultaneously with the shifting of said cam on said shaft to vary the time of injection as the injection period is varied, and manually controlled means for varying the speed range of the governor.

4. In a circuit controller for fuel injection systems, the combination with a switch including a movable contact, of a. timing shaft,

a cam on said shaft for controlling said movable cont-act, said cam being slidabl mounted on said shaft and having a varia le profile shiftable relatively to said movable contact to vary the duration of the circuit closing period of said switch to vary the duration of the injection period, an engine-driven shaft, and a driving connection between said shafts including a pin and a member slidably mounted on said timing shaft'and associated with said cam and having an angularly disposed slot in which said pinworks whereby to angularly shift said cam and timing shaft simultaneously with the shifting of said cam on said shaft to vary the time of injection as the injection period is varied.

5. In a circuit control mechanism for fuel injection systems, the combination with a switch .including a movable contact, of an engine-driven cam for operating said contact and having a variable profile shiftable lengthwise relative to said movable contact to vary the duration of the circuit closing periods, a governor, and means controlled by the governor for angularly shifting said cam for advancing or retarding the timing of the injection periods independently of said cam profile but simultaneously with the change of duration of the circuit closing period whereby the timing and the amount of the fuel charge at a given engine speed will be suitable for good power performance.

6. In a fuel injection system, circuit control mechanism for a metering control electromagnet comprising a switch including a movable contact, an engine-driven cam for operating said contact, a governor, means operated by said governor for adjusting the cam and switch relative toeach other to vary the duration of the circuit closing periods of said switch, said cam providing relatively longer circuit closing periods at intermediate speed than at higher speeds whereby greater charges of fuel are furnished to the enginne at intermediate speeds than at higher speeds. Y

'7. In a circuit controller for fuel injection systems, the combination with a switch including a movable contact, of an enginedriven shaft, a timing shaft, asleeve on said timing shaft having an inclined slot, means including a pin associated with said slot and forming a driving connection between said engine-driven shaft and said sleeve, a cam on said timing shaft for operating said contact and movable lengthwise .of and rotating with said shaft, a key connecting said cam and sleeve and slldably mounted in a keyway in said shaft, means for imparting a lengthwise movement to said sleeve to cause the same to move simultaneously lengthwise and angularly relative to said pin to change the timing relation of said cam relative to said contact whereby to control the time of and the duration of the circuit closing period of said switch.

8. In a circuit controller for fuel injection systems, the combination with a switch including a movable contact, of an enginedriven cam controlling the movement of said contact and having a variable profile shiftable lengthwise to vary the circuit closing period of said switch and angular-1y to change the cyclietiming of said period, a speed-responsive member controlled by the 10 engine, and means for transmittinglengthwise movement to said cam in equal propor tion to the movement of said speed-responsive member and angular movement to said cam in variable proportion to the movement of said speed-responsive member whereby for a. given engine speed the duration and timing of the injection period will be suit able for good power performance.

In testimony whereof, I aflix my signature.

LOUIS O. FRENCH. 

